Power operated door opener



I Fell 20, 1968 G. R. MILLARD ETAL 3,369,323

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,Feb 20, 1968 G. R. MILLARD ETAL 3,369,323

POWER OPERATED DOOR OPENER Original Filed July 2. 1964 5 Sheets-Sheet .2

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50 5/ 5517i. JJ? 2? .6 F527 J2 ig Peb. 20, 1968 R. MILLARD ETAL POWEROPERATED DOOR OPENER Original Filed July 2. 1964 5 Sheets-Sheet 3 .www@NIJ INVENTORS Geo/ge E AAM/0rd Raz/mond R. Maf/m z3/*ace Vde/manreor/ck Q ffm/ 6 Bf www y AT TO RNEY om /l V Zvw@ United States Patent O3,369,323 POWER OPERATED DOOR OPENER George R. Millard, 115 E. Canal,Tekonsha, Mich. 49092; Raymond R. Martin, R.R. 3, Albion, Mich. 49224;and Bruce B. Bidelmau, 209 W. Hughes, and Frederick D. Hicks, 322Ferguson Road, both of Marshall, Mich. 49068 Continuation of applicationSer. No. 379,932, July 2, 1964. This application Mar. 22, 1967, Ser. No.625,270 16 Claims. (Cl. 49-137) ABSTRACT OF TI-IE DISCLOSURE A hydrauliccylinder and piston rod connected to reciprocate a cam, a crankconnected to the door and actuated by the cam, springs arranged to closethe door; hydraulic valves connected to the ends of the cylinder yand toeach other, coacting closure parts on the valves and piston, andpassages in the valves to provide full flow followed by restricted flowat the end of the door opening motion, and full flow followed byprogressively restricted flow at the end of the door closing motion ofthe piston; and fluid recirculating passages with a spring pressedbypass valve providing constant hold open pressure on the door. Amechanical connection between the cam and crank permits emergencyopening of the door.

This applic-ation is a continuation of copending applioation Ser. No.379,932, tiled July 2, 1964, now abandomed.

Objects and advantages of the invention will be apparent from aconsideration of the following description and claims. The drawings, ofwhich there are three sheets, illustrate a highly practical form of thedoor operator.

FIG. 1 is a fragmentary outside elevational view partially broken awayin section of the top of a door and door frame header having the poweroperator of the invention mounted therein.

FIG. 2 is a fragmentary cross sectional View through the door operator.mechanism taken along the plane of the line 2--2 in FIG. 1 and showingthe door operator in door closed position.

FIG. 3 is a fragmentary cross sectional -view similar to FIG. 2 butshowing the door operator in full door opening position.

FIG. 4 is a fragmentary transverse cross sectional view taken along theplane of the lines 4--4 in FIGS. 1, 2

. and 5.

FIG. 5 is an enlarged fragmentary vertical longitudinal cross sectionalview taken along the plane of the line 5 5 in FIG. 4.

FIG. 6 is -a fragmentary top plan view partially in section of theanchor connections to the outer or left end of the door operatorcylinder and the door closing springs as these parts would be viewed inlooking downwardly at the top side of the installations in FIGS. 4 and5.

FIG. 7 is a fragmentary side elevational view of the cylinder anchoringmember shown in FIG. 6 with `a por tion of the cylinder connectedthereto.

FIG. 8 is an inner or right end elevational view of the cylinder anchorand valve body shown in FIGS. 6 `and 7.

FIG. 9 is an outer or left end elevational view of the cylinder anchorand valve body shown in FIGS. 6 to 8.

FIG. 10 is an enlarged fragmentary vertical cross sectional view takenalong the plane of the broken line 10--10 in FIG. 3 showing the inner orright hand end of the cylinder and return spring anchor and valve body.

FIG. 11 is a fragmentary transverse cross sectional view taken along theplane of the line 11-11 in FIG. 10.

FIG. 12 is an enlarged bottom plan view of the inner ICC FIG. l5 is afnagmentary outer or right elevational view of the right valve bodyrelative to the cylinder shown in FIGS. 12 to 14.

FIG. 16 is a transverse cross sectional view taken along the plane ofthe line 16-16 in FIG. 12` looking in the direction of the arrows.

FIG. 17 is a transverse cross sectional view taken along the plane ofthe line 17-17 in FIG. 12 looking in the direction of the arrows.

FIG. 18 is a cross sectional view taken along the plane of the line 1818in FIG. 13 looking in the direction of the arrows.

FIG, 19 is a transverse cross sectional view taken along the plane ofthe line 19-19 in FIG. 12 looking in the direction of the arrows.

FIG. 20 is'a fragmentary longitudinal cross sectional view taken alongthe plane of the line 2li- 20 in FIG. 15 looking in the direction of thearrows.

The door operator or opener of the invention as shown in FIG. 1 isdesigned to be mounted in a transom or header member 1 of a door framehaving a left upright 2 and right upright 3 with a door 4 swinginginwardly of the plane of the picture from the right side. The framemembers illustrated are extruded aluminum sections and a fragment of aglass panel 5 is illustrated above the door. The operator mechanismindicated generally by the numeral 6 is enclosed in the header 1 whichis of downwardly opening channel shaped cross section with inwardlyprojecting ribs 7 near the lower ends of the side walls for supportingbottom closure plates S and 9 (see FIGS. 5 and 11) as will be describedpresently. The same door operator may be installed in doors of 'varyingwidths and the header 1 is mounted between the side frame members 2 and3 by Ushaped clips 101 and 11.

The clips are secured to the side frame members by screws 12 engaged inblocks or nuts 13 on the inner sides of the side frame members and theside frame members are provided at the proper height with openings 14through which the nuts 13 may Ibe pressed into position. The U-shapedend clips 10 land 11 are provided with central openings 15 ofsubstantial size through which access may be had to the openings 14 andthe nuts 13- and through which a supply pipe or conduit 16 and a returnpipe or conduit 17 from a suitable remotely located pump or source ofhydraulic pressure may rbe passed.

The pump may be started by any suitable means such as a pressure matswitch positioned on both sides of the door for automatic operation asis common or when multiple doors are installed in a single position thepump m-ay be operated continuously and the supply of hydraulic liquid toeach door may be controlled by a. valve actuated by the mat switch orother control. Details of the pump, switch or valve form no part of thepresent invention -and so are not illustrated.

The door operator 6 as shown in FIGS. 2 and 3 consists generally of apair of outer or left end support plates 18 and 19 which are securedtogether in vertically spaced relation by screws 20 passed throughspacers 21 at the corners of the plates. For the purpose of description,the left or pivoted edge of the door will be considered as the outeredge, to which the outer end of the door opener eX- tends, asdistinguished from the inner end of the opener which ,may be located atan indeterminate distance inwardly of this edge in wider doors. Theplates 18 and 19, of which the plate 18 is the lower, constitute`anchoring or mounting means for the central hydraulic cylinder 22 whichopens the door, and a pair of coiled compression springs 23 enclosed inthe cylindrical casings 24 which close the door. At the right or innerend of the door operator the cylinder 22 is mechanically connected andsealed to a rst or inner valve body 25 and the spring casings 24 areretained against the sides of the valve body by an annular band 26. Theplates 18 and 19 constitute anchoring means for the cylinder 22 and forjournals or bearings 27 and 28 for a crank member 29. The crank memberhas lower noncircular end 30 nonrotatably and drivingly engaged in thedoor 4 so that rotation of the crank by the operator as will bedescribed rotates the door in an opening and closing motion. The inletor supply conduit 16 and return conduit 17 are connected to the innervalve body 25 through a connecting plate 31.

Turning first to the mechanical opening and closing mechanism at theleft end of the door operator as shown in FIGS. 2 to 9 it will be notedthat the spaced guide plates 18 and 19 have opposed guide slots 32 ontheir opposed inner sides extending longitudinally of the header andconstituting guides for eight rollers 33 positioned at the corners of acam plate 34. The cam plate denes a central aperture or opening throughwhich the segmentally shaped center portion 36 of the crank 29 extends.

The plate 34 has a laterally opening slot 37 formed therein and openingfrom the side of the central aperture 35 with a slightly outwardlyprojecting nose 3S at the transversely and longitudinally inner end ofthe slot. The crank 29 has spaced parallel arms 39 connected to the endsof the segmental central portion 36 positioned on opposite sides of thecam plate 34 and projecting radially from the axis of the crank whichcoincides with the swinging axis of the door. The swinging ends of thecrank arms support a follower in the form of a roller 40 carried by apin 41 extending between the crank arms and the roller which is sized tot closely within the slot 37.

Outward extension of the cam plate to the left as shown in FIG. 3engages the longitudinally inner side edge of the slot 37 with thefollower roll 40 to swing the crank arms 39 approximately 90 to the dooropening position. Conversely inward retracting motion of the cam plateto the right causes the longitudinally outer edge of slot 37 to swingthe crank clockwise as viewed in FIGS. 2 and 3 to close the door. Tolimit and cushion the opening motion of the door the bottom guide plate18 is provided with a stop block or plate 42 located by dowels 43 andsecured by a screw 44. The stop block has an abutment surface or edge 45against which the lower crank arm 39 abuts in the open position of thedoor as appears in FIG. 3. The stop plate or block has an opening orslot 46 formed therein behind the abutment 45 so that the abutment mayyield slightly and cushion the stop of the open- .ing motion.

The cam plate 34 is actuated by the piston rod 47 extending from thepiston 48 in the cylinder 22. The outer or left end of the cylinder 22is mechanically anchored and sealed to a second or outer valve body 49having a cylindrical inner projection 50 to which the cylinder iswelded. At its outer or left end the valve body 49 has tongues 51 withribs 52 on their upper and lower sides. The ribs t within transverseslots or grooves 53 formed in the inner sides of the anchor plates 18and 19 and screws or bolts 54 further secure the valve body to theanchor plates. The anchor plates are in turn secured to the inwardlyprojecting flanges 7 of the header by screws 55 (see FIG. 5) so that thecylinder and outer valve body 49 are xed relative to the header.

The sides of the outer valve body 49 have concave side surfaces 56 whichreceive the sides of the spring casings 24 and dowel pins 57 projectingfrom the inner ends of the mounting plates form sockets which retain theouter ends of the spring casings 'against the sides of the valve body.

Compression in the spring 23 holds the spring casings against the innerends of the mounting and guide plates. The outer end of the piston rod47 is connected to a yoke 58 pinned to the inner end of the cam plate at59. The pins supporting the inner corner guide rollers 33 on the camplate support U-shaped yokes 60 which are engaged by hooks 61 on pullrods `62 projecting through the coil springs 23. Washers 63 at the innerends of the pull rods and springs engage eyes 64 on the pull rods sothat left or outward extension of the cam plate 34 by the piston rod 47compresses the springs 23. Release of pressure by the piston 48 on thepiston rod 47 permits springs 23 to expand retracting the pull rods 62and the cam plate 34 inwardly or to the right.

The outer or left valve body 49 defines a central sealing journal 65 forthe piston rod 47 with an annular enlarged space 66 therearound on theinner end of the valve body. A rst radial port or passage 67 plugged atthe outer end communicates between the annular space 66 and an axiallyextending bore 68 opening from the inner end of the valve body 49externally of the cylinder 22. A return connecting pipe 69 connects theport 68 with the inner valve body as will be described presently. Theouter valve body also denes an axially extending port or bore 70 whichis continuously open Within the cylinder 22 and which communicatesthrough the bore 71 with a vertical bore 72 formed upwardly from thebottom of the valve body. The bore 71 is blocked at its outer end. Thebore 72 is enlarged at '73 and communicates with the annular passage 66through a port 74 which may be a continuation of the port 67. A needlevalve 75 threaded adjustably in the further enlarged outer end 76 of theport 73 variably adjusts the opening between the port 73 and the port orbore 70.

The piston rod 47 carries an abutment 77 within the cylinder backing upa coil spring 78 which in turn yieldably forces a closure member orvalve 79 outwardly upon extension of the piston and piston rod. Thusduring initial opening motion of the door, oil within the left or outerend of the cylinder passes freely through the annular recess 66, port 67to the port 68 and return pipe 69. Rapid opening motion of the door isthus assured. As the closure or valve 79 engages the end of the outervalve body, it closes off the annular passage 66 as appears in FIG. 3and the only remaining passage for escape of oil from behind the pistonis through the port 70 and bores 71, 72, past the needle valve 75 andport 74. Adjustment of the needle valve in the threaded bore 76accordingly determines the speed of the final opening movement of thedoor.

The connecting or return pipe 69 extends to the outer face of the innervalve body 25 and connects thereto externally of the cylinder 22 to abore 80 at the outer face of the valve body relative to the inner end ofthe operator. The bore 80 extends approximately half way through thebody 25 and intersects and communicates with the larger return bore 81to which the liquid return pipe or conduit 17 connects. A free return orow of oil between the outer valve block and the return conduit 17 isthus open at all times. The delivery or supply conduit 16 opens into avalve bore 82 which extends to a dead end in the valve body 25 andcontains a coil spring 83 positioned behind and biasing a spool-likecontrol valve 84 outwardly of the bore 82 (inwardly of the operatortoward the inner end of the inner valve body). The spool valve 84 has acentral axial bore 85 communicating with radial bores 86 which open tothe annular space in the center of the spool valve. Moving progressivelyinwardly of the bore 82 toward the cylinder 22 from the outward positionof the valve in the bore, the valve body 25 has a rst cross bore 87plugged at its outer end and communicating between the bore 82 and aninlet passage 88. The inlet passage 88 is bored from the inner face ofthe valve body relative to the cylinder (see FIG. 14) to open into thecylinder and is enlarged at its inner end to rcceive a ball check valve89 retained in the bore by a pin 90. Thus as pressure developed in theinlet or delivery conduit 16 builds up, the spool valve 84 is forcedinwardly until the annular reduced center of the spool and the bore 8Scommunicate with the cross bore 87 and the axial bore or inlet passage88 so that oil under pressure passes freely around the check valve 89and into the inner end of the cylinder 22 forcing the piston 48 andpiston rod 47 to extend and open the door.

To control the opening speed of the door, inlet passage 88 communicates,intermediate of its length at section and FIGURE 17, with theintermediate section of a stepped bore 91 bored upwardly'from the bottomof the valve body. The bore 91 adjustably receives the threaded needlevalve 92, the reduced inner end of which coacts with the reduced innerend of the bore. Valve 92 constitutes a door opening speed controlvalve. The reduced inner end of the bore 91 intersects the return bore81 at 93 so that opening of valve 92 bleeds off` part of the oil andpressure, which would otherwise actuate the piston, directly to thereturn conduit 17. The speed of the initial opening movement of the dooris thus controlled by adjustment of the valve 92. Note that theby-passed oil also effects the volume and speed of the oil that can 4beexpelled from the outer end of the cylnider through the connecting pipe69. As the door nears open position, valves 79 and 73 in the outer valvebody assume control of the opening speed of the door as previouslydescribed.

When the door is fully opened with crank arm 39 against stop surface 45of plate or block 42, the resistance to displacement of oil builds uppressure on spool valve 84 so that the spool moves inwardly of bore S2until the annular reduced center portion of the spool also uncovers atransverse passage 94 bored from the side of the body 25 and plugged atits outer end and extending across the body to return passage 81 (seeFIG. 18). The reduced annular center of spool valve 84 opens to bothpassages 87 and 94 so pressure is maintained on piston 48 to hold thedoor open while excess oil is recirculated through passages 94 and 81 tothe return conduit 17. A third cross passage 95 having the sameconnections as passage 94 bleeds oil from behind spool valve 84 so thevalve can operate freely under the inuence of spring 83 and pumppressure.

When the contr-ol (mat switch, push button or other) shuts o thepressure by stopping the pump or closing a control valve, pressure onthe spool valve 84 and piston 4S is removed. Spring 83 moves spool valveto close oif passages 87 and 94. Springs 23 start to retract the pistonandclose the door. Check valve 89 closes the inner end of inlet passage88.

Oil trapped in the inner end of cylinder 22 escapes initially through ahollow needle valve 96 slidable in a bore 97 formed in the outer face ofbody 25 coaxial with the cylinder. Oil may also flow through a V-shapednotch 98 in the end of the bore past a collar 99 on the needle valve.The needle valve is biased inwardly of the cylinder by a spring 100 (seeFIG. 2). The expelled oil flows through bore 97 to an intersection witha vertical bore 101 drilled down from the top of the body and plugged atits outer end. The bore 101 intersects a cross bore 102 also plugged atits outer end and communicating with the inner end of a second steppedbore 103 formed upwardly from the bottom of the valve body. A secondneedle valve 104 coacts with the small end of stepped bore 103 toregulate the flow of oil into the intermediate section of the bore thatintersects passage 88 at 105. Passage S8 thus becomes an outlet passageto return pipe or conduit 17. Valve 104 is adjustable from the bottom ofthe valve body in threads 106 and constitutes a door closing speedcontrol valve.

As the door approaches closed position, piston 48 approaches theinwardly projected position of needle valve 96. A socket 107 in theinner end of the rod 47 receives the end of the tubular needle valve andcuts olic the major portion of the flow through the needle, slowing theclosing motion. Some flow continues through a groove or notch 108 in theoutside of the needle valve that is not closed oif by the wall of thesocket. Other iow continues through the notch 93 around the collar onthe needle valve but the ow of expelled oil and the closing speed of thedoor is reduced. As the piston retracts further, needle valve 96 ispushed out of the cylinder against spring and collar 99 moves out pastthe notch 98 so flow through the notch is cut off, further reducing theclosing speed of the door. The nal closing motion under the force ofsprings 23 is positive but gentle as the lastY of the oil escapesthrough notch 108.

The circulating flow of oil through the several passages, to and fromboth ends of the cylinder to the pump prevents oil in the operatingsystem from cooling or varying substantially in temperature from thetemperature of oil in the pump. The operation of the door operator isthus uniform and reliable under different weather conditions.

The door operator unit is relatively inexpensive to assemble andinstall. The connections of the outer ends of the cylinder and thespring casings to the outer valve body have been described. The innervalve body 25 has a cylindrical projection 109 over which the inner endof the cylinder is sleeved, and secured by rolling or crimping a bead110 into the groove 111 in the projection. Groove 112 holds a liquidseal or packing for the end of the cylinder. The sides of the innervalve body are concave at 113 to receive the sides of the springczasings 24. A tie band 26 holds the spring casings to the valve body2S. Dowel pins 57 (see FIGS. 4 and 5) hold the outer ends of thecylindrical spring casings 24 against concave sides 56 of the outervalve body 49. The compression of spring 23 holds the springs andcasings against the guide plates 13 and 19.

While all the cooperating loads and forces of the operator arelocalized, supported and resisted by the connection of the plate 18 tothe ange 7 of the header and abutment of the plates 1Sy and 19 againstthe left header supporting clip or bracket 10, the weight of the innerend of th-e operating unit may be supported by screws 116 passed throughears 117 on the inner valve body and ltappeti into holes in the top ofthe header or transom. This takes all load off of the connections to thesupply and return pipes 16 and 17. The operator may be installed inother headers or below threshold plates of a doorway frame as will beunderstood.

The inwardly projecting flanges 7 are cut away in the center as at 118so that the operator may be assembled as a complete unit and lifted intothe header. After the valves 75, 91 and 104 are adjusted to obtain thedesired speed of operation, the bottom closure plates 8 and 9 aresecured in place to conceal the operator and provide a neat appearingheader.

Should building codes or regulations require emergency openingcapabilities in the opposite direction from the powered open position ofthe door, outward pressure on the door will turn the crank 30, 36 andarms 39 to move the follower roll 40 over the nose 38 by pressing thecam plate 34 and piston 48 slightly to the right. Pressure developed inthe right or inner end of the cylinder by this slight movement istransmitted through valve body 25 behind valve 84 to return pipe 69. Thecrank arms 39 are then free to swing the follower roll in the camopening 35 to the emergency open position shown. in dotted lines at 40in FIG. 2 without resistance from the springs 23 or pressure in thecylinder. If emergency opening is desired the usual door stop strip 119must be of a breakaway type, several of which are well known.

The inclined edge 120 at the longitudinally outer side of the slot 37,urged against the follower roll 40 by inward extension of the springs 23is approximately perpendicular to the crank arms 39 in the closedposition of the door, thus effectively resisting wind pressure tendingto open or rattle the door.

The outwardly curved contour of the side edge of nose 3S brings theinitial opening motion contact of the cam plate approximatelyperpendicular to the radius of the crank arms and motion of the followerroll for maximum mechanical advantage of the cam plate and piston instarting the opening motion of the door. As the follower 40 moves out inthe slot 37, the pressure from the cam plate remains approximatelyperpendicular to the radius of the crank arm. This reduces the powerrequirements for operating one or more operators from a single pump. Theinitial, door closed, position of the crank arms 39 can be varied bycorresponding variation of the position or shape of the slot 37 as willbe understood. The direction of powered operation of the piston 48 andcam plate 34 may also be reversed by suitable reversal of the valveblocks and positioning of the cam plate and crank arms, withoutdeparting from the theory of the invention as defined in the followingclaims. What is claimed as new is:

1. A power operated door opener adapted to be connected to a source ofhydraulic pressure and including a crank engageable with a door alongthe swinging axis of the door, and coacting cylinder and piston rodmembers movable in door opening direction under hydraulic pressure, andspring means connected between said cylinder and piston rod members toreturn the members in door closing direction,

said opener being characterized by fixed guide means attachable to adoor frame member adjacent said crank,

means anchoring one of said members to said guide means,

coacting cam and follower means connected to said crank and the other ofsaid members and guided by said fixed guide means to swing said crank todoor open position upon opening motion of said other of said members,

first and second valve bodies connected to and closing the ends of saidcylinder member with said piston rod member extensible in sealingrelation through the first of said valve bodies,

a piston on said rod member within said cylinder member,

a first passage formed through one of said valve bodies with its endsopening interiorly and exteriorly of the cylinder member,

a closure yieldably carried by said piston rod and movable therewithinto closing relation with the interiorly opening end of said firstpassage near the end of the door opening motion of said members,

a second passage formed in said one valve body with one end opening tothe interior of said cylinder and unobstructed by said closure and withits other end opening to said first passage intermediate of the ends ofthe first passage,

a fluid return passage extending through the other of said valve bodiesand having a fluid return connection to a pressure source connected toone end,

means forming a fluid connection between the exteriorly opening end ofsaid first passage and the other end of said return passage,

a valve bore formed in the other of said valve bodies and having aclosed inner end,

a pressure supply conduit connected to the open outer end of said Valvebore,

a valve slidable in said valve bore and biased to the outer end of thebore by a spring in the inner end of the bore,

an inlet passage formed in'said other of said valve bodies and havingone end opening to the interior of the other end of said cylinder memberand its other end opening to said valve bore at a point inwardly of thespring biased position of said valve,

a check valve in said inlet passage seating against escape of fluid fromsaid other end of said cylinder,

:t pressure relief passage formed in said other valve body and havingone end opening to said valve bore at a point spaced inwardly of thebore relative to the opening of said inlet passage to the valve bore,

the other end of said relief passage opening to said return passage,

an outlet passage formed in the other of said valve bodies with one endopening to the interior of the other end of said cylinder member andwith its other end opening to said inlet passage at a point outwardly ofsaid check valve relative to the interior of said cylinder member,

a fiow reducing valve coacting with the end of said outlet passage andmovable to iiow restricting position by relative movement of said pistonrod and cylinder members to adjacent door closing position,

spring means biasing said fiow reducing v-alve toward opennonrestricting position and against relative door closing motion of saidpiston and cylinder members,

and means forming a reduced ow passage from the interior of the otherend of said cylinder member to said outlet passage as said flow reducingvalve is moved to restricting position by final door closing motion ofsaid members.

2. A door opener as defined in claim ll in which there is a bypasspassage formed in the other of said valve bodies between said inletpassage and said return passage.

3. A door opener as defined in claim 2 in which there is an adjustableopening speed control valve in said bypass passage.

4. A door opener as defined in claim 3 in which there is a secondadjustable closing speed control Valve in said outlet passage.

5. A door opener as dened in claim 4 in which there is. a. thirdadjustable opening speed control valve in said second passage in saidone of said valve bodies.

6. A door opener as defined in claim 5 in which said fiow reducing valveis reciprocably mounted in said outlet passage with one end projectinginto the path of closing motion of said rod member.

7. A door opener as defined in claim 1. in which said one of said pistonrod and cylinder members anchored to said guide means is the cylindermember, and the coacting cam and follower means yare connected to thepiston member.

8. A door opener as defined in claim 7 in which one of said valve bodieshaving said first and second passages formed therethrough is said firstvalve body through which said rod member projects, and the other of thevalve bodies is the second valve body to which the fluid returnconnection and supply conduit are connected,

the rod member of the opener -being extended from the cylinder member toopen the door.

9. A door opener as defined in claim 8 in which the cam of said coactingcam and follower means is connected to said rod member and guided bysaid guide means, with the follower connected to said crank.

10. A door opener as defined in claim 9 in which said guide means arespaced plates having bearings therein for said crank and parallel trackson their opposed faces,

said cam means being formed in a cam plate connected to said rod member,

and rollers on the corners of said cam plate guidingly engaged betweensaid tracks.

11. A door opener as defined in claim 10 in which said cam means is anopening formed thro-ugh said cam plate with a slot extending from oneedge of the opening, transversely of the lines of said tracks,

said follower means being a roller carried by said crank and closelyfitting in said slot.

12. A door opener as defined in claim 11 in which there is a reentrantcurved nose at the intersection of the edge of said slot and the openingat the side of the slot located closest to said cylinder member,

the opening in said cam plate inwardly of said nose being large enoughto receive said follower roll upon manual opening of the door in adirection opposite to the opening motion of the door by said piston rod.

13. A door opener as dened in claim 12 in which there is a surface yatthe intersection of said opening and the opposite side of said slot fromsaid cylinder member, which surface is generally parallel to the arm ofsaid crank and engageable with said follower roll in the closed positionof the door.

14. A door opener as defined in claim 11 in which there is a stop platesecured to one of said guide plates and having an edge engageable withsaid crank in the opened position of said door,

said stop plate having a slot formed therein to yield- `ably oppose nalopening motion of said door.

15. In combination with a door frame having a hollow header and a doorswingably mounted therein with supply and return conduits extending tosaid header, a powered door opener comprising,

a guide plate secured within one end of said header,

a crank member journaled in said guide plate and having a depending endrotatably drivingly engaged with the upper edge of said door along theswinging axis of the door,

a cam plate slidably and guidingly engaged for longitudinal motionrelative to said guide plate,

a cam opening formed in said cam plate and through which said crankmember extends,

said cam opening having a transversely extending slot opening from oneside thereof with a reentrant curved nose on the inner side and end ofsaid opening relative to the longitudinal path of said cam plate,

a follower on said crank member engageable in said slot,

spring rods secured to the longitudinally inner end of said cam plateand extending longitudinally inwardly therefrom,

compression coil springs surrounding said rods and abutted at theirlongitudinally outer ends against the inner end of said guide plate,

a first valve body having one end xedly secured to the inner edges ofsaid guide plate,

a second valve `body positioned between said compression springs attheir longitudinally inner ends,

compression members on the longitudinally inner ends of said rods tocompress said springs upon longitudinal outward motion of said camplate,

a hydraulic cylinder extending between and sealingly connected to saidvalve bodies,

a piston reciprocable in said cylinder and having a piston rod connectedthereto and extending in sealing relation through said first valve bodyand connected to the inner end of said cam plate,

a rst liquid return passage formed in said rst Valve body from withinsaid cylinder,

a liquid return pipe connected to said first return passage andextending to a return passage formed in said second valve body andcommunicating with said return conduit from said pump,

an inlet valve lbore formed in said second valve body and connected tosaid supply conduit, an inlet passage formed in said second valve bodyand communicating between said valve bore and the inner end of saidcylinder with a check valve therein closing toward said valve bore,

a first valve member slidingly mounted in said Valve bore and springbiased toward said supply conduit into closing relation with said inletpassage,

a pressure relief passage formed between said inlet valve bore and saidreturn passage in said second valve body on the opposite side of theinlet passage from said supply conduit,

a bleed passage formed between said valve bore and said return passageon the opposite side of the opening of said pressure relief passage tosaid valve bore to vent said bore behind said rst valve,

a bypass passage formed in said second valve body and opening betweensaid return passage and said inlet passage,

an outlet passage formed in said second valve body opening to saidcylinder and communicating with said inlet passage on the opposite sideof said check Valve from said cylinder,

an axially yieldably mounted second valve element mounted in coactingrelation to said. outlet passage between said piston and said secondvalve body and forming a rst outlet opening from said cylinder,

said second valve element defining a second outlet opening closed in theyieldably displaced position of the second valve element,

said piston and said second valve body coacting to displace said secondvalve element to obstruct said second outlet opening in the inwardlyretracting position of said piston,

an adjustable restricting valve in said bypass passage in said secondvalve body,

and another adjustable valve in said second valve body positioned torestrict the outlet passage therein.

16. A powered door opener in the combination as dened in claim 15 inwhich there is a stop plate secured to said guide plate and having anedge engageable with said crank in the door open position of the crank,

said stop plate having a slot formed therein whereby the stop plateyields under door opening motion of said crank.

Retel'ences Cited UNITED STATES PATENTS 2,789,814 4/1957 Carlson 49--1372,869,861 1/1959 Carlson 49--138 3,129,936 4/1964 Carlson` 49-264 DAVIDJ. WILLIAMOWSKY, Primary Examiner.

J. KARL BELL, Assistant Examiner.

